Pan-Canadian Standards use Object Identifiers (OIDs) to distinguish between objects by assigning a numeric string that enables other systems to understand the unique information that is being shared between various systems.
- OIDs are intended to be globally unique and never re-used
- OIDs in the pan-Canadian standards identify terminology code systems and are transmitted in HL7 messages
- OIDS used to identify terminology subsets are not transmitted in HL7 messages, rather these OIDs are used for vocabulary maintenance and Terminology Services
- OIDs are used to qualify local identifiers (e.g. patient identifiers) such that the combination of an OID (assigning authority) and a local identifier remains globally unique